Is it possible to create a Spy function that returns an object that keeps track of how many times a function is called like shown below?
var spy = Spy(console, 'error')
console.error('calling console.error')
console.error('calling console.error')
console.error('calling console.error')
console.log(spy.count) // 3
You could wrap the call to the method
class Spy {
constructor(obj, method) {
this.count = 0
const _method = obj[method] // save the ref to the original method
const self = this
// wrap the method call with additional logic
obj[method] = function () {
self.count++
_method.call(this, ...arguments)
}
}
}
var spy = new Spy(console, "error")
console.error("calling console.error")
console.error("calling console.error")
console.error("calling console.error")
console.log(spy.count) // 3
you can use javascript Clouser property.
// Initiate counter
let counter = 0;
// Function to increment counter
function add() {
counter += 1;
}
// Call add() 3 times
add();
add();
add();
// The counter should now be 3
reference https://www.w3schools.com/js/js_function_closures.asp
console.logby yourself